M10 × 1.25 Tap Drill Size & Thread Specs
Everything for a M10 × 1.25 fine pitch thread on one page: tap drill (8.8 mm), clearance holes, wrench and hex key sizes, and the nearest inch thread.
SP-TD-01 · M10 × 1.25
M10 × 1.25 specs
SizePlate
M10 × 1.25 · tap with
8.8 mm drill
.3465″
8.8 mm · 74% thread
- Inch drill
- S · .3480
- Clearance
- 10.5 / 11 mm
- Wrench
- 16 mm
- Cap screw key
- 8 mm
Thread
Drilling
- Tap drill
- 8.8 mm · .3465
- Inch substitute
- S · .3480
- Close fit
- 10.5 mm
- Normal fit
- 11 mm
- Free fit
- 12 mm
Tools
- Hex head (ISO 4017)
- 16 mm
- Hex head (DIN 933)
- 17 mm
- Socket head cap key
- 8 mm
- Button head key
- 6 mm
- Flat head key
- 6 mm
Nearest inch
- Thread
- 3/8-16
- Major diameter
- .3750″
- Threads per inch
- 16
- Tap drill
- 5/16
- Interchangeable
- No
Not interchangeable means the threads look close but won't run together: forcing one into the other strips both.
Drill size by thread percentage
Larger drill, less thread, easier tapping. 75% is the usual target.
| Drill | Decimal | mm | Thread |
|---|---|---|---|
| 8.7 mm | .3425 | 8.7 | 80% |
| 11/32 | .3438 | 8.73 | 78% |
| 8.8 mm | .3465 | 8.8 | 74% |
| S | .3480 | 8.84 | 71% |
| 8.9 mm | .3504 | 8.9 | 68% |
| 9 mm | .3543 | 9 | 62% |
| T | .3580 | 9.09 | 56% |
| 9.1 mm | .3583 | 9.1 | 55% |
| 23/64 | .3594 | 9.13 | 54% |
| 9.2 mm | .3622 | 9.2 | 49% |
Neighboring sizes
- M8 × 1.25tap 6.8 mm
- M8 × 1.0tap 7 mm
- M10 × 1.5tap 8.5 mm
- M10 × 1.0tap 9 mm
- M12 × 1.75tap 10.2 mm
- M12 × 1.5tap 10.5 mm
Questions
What does M10 × 1.25 mean?
An ISO metric thread with a 10 mm major diameter and a 1.25 mm pitch (the distance from one thread crest to the next). It’s the fine pitch for M10.
Can I use a S drill instead?
Usually. S is .3480″ against .3465″ for the 8.8 mm drill, which changes the thread engagement by a few percent at most.